An industrial robot is designed to hold a robot hand on the free end of the wrist thereof and is constituted for various robot actions, such as gripping a workpiece with the robot hand, transporting a workpiece between a plurality of positions, and assembling motions. In order to carry out these robot actions, the arm joined to the robot body, the wrist joined to the free end of the arm, and the hand held by the wrist, each have a certain degree of freedom, to enable movement and positional changes of the robot hand within a space for the desired robot actions. Accordingly, the wrist joined to the free end of the robot arm has a mechanism generally of two or three degrees of freedom. When the wrist mechanism has plural degrees of freedom, particularly when the wrist comprises internal differential units, the turning motion of the external mechanism is liable to cause fundamentally unnecessary movements, generally known as "dragging drift", of the wrist. In general, the dragging drift of the wrist is compensated by the correcting action of the driving source of the wrist mechanism, until the robot hand holding part of the wrist is located at a desired position in a desired attitude.